The present invention relates generally to electromagnets and dynamoelectric machines. More particularly, this invention relates to a wedge and spring assembly for securing coils supported on salient poles in electromagnets and dynamoelectric machines.
Prior art devices for securing or retaining such coils which have a number of turns of wire used to produce a magnetic field and which are supported on salient poles in electromagnets and dynamoelectric machines having a plurality of circumferentially spaced and axially extending salient poles, have generally included mechanical fastening means or adhesive means. Typical mechanical fastening means include solid nonmagnetic spacers which are bolted to the magnet structure, e.g., a stator of a dynamoelectric machine.
Common adhesive fastening means for securing such coils onto associated salient poles include epoxies, which once cured become so rigid that it is virtually impossible to remove the coils from the salient poles for repair or replacement.
Another approach for retaining coils on salient poles is shown in U.S. Pat. No. 2,764,802 granted to Feiertag. Feiertag discloses a method for assembling a field coil on a stator which has stator poles consisting of layered segments extending circumferentially inward. In his method, a field coil is placed over a layered stator pole and a pair of longer segments of the pole are bent across the inner exposed surface of the field coil to form a C-channel within which the field coil is held in place. However, such a method does not resist the Lorentz forces generated in the coil due to electrons in the coil moving through electric and magnetic fields which during operation of electromagnets and dynamoelectric machines tend to force the coils away from the salient poles and toward the opening in the formed C-channel.